Author Topic: FGM Raised Dome long awaited Modified Throat  (Read 8884 times)

0 Members and 1 Guest are viewing this topic.

Offline TXCraig1

  • Registered User
  • Posts: 16217
  • Location: Houston, TX
    • Craig's Neapolitan Garage
Re: FGM Raised Dome long awaited Modified Throat
« Reply #25 on: January 31, 2013, 07:23:30 PM »
How are you firing?  In my opinion the reason I was able to get the little oven hot so fast was that I could completely fill it with wood.  My best results came from building a cabin in the middle AND a ring around the perimeter of splits stacked like fallen dominoes if that makes sense.  I could light it and walk away.  The perimeter wood would burn last and once it was done it was ballistic.

When I talk about it taking 10 hours to get mine ready, I'm starting with about 4 medium-small logs and then burning 1-2 medium-medium-large logs at a time for the balance of the 10 hours.

I need to try your way sometime and see how it goes.
"We make great pizza, with sourdough when we can, commercial yeast when we must, but always great pizza."
Craig's Neapolitan Garage


Offline TXCraig1

  • Registered User
  • Posts: 16217
  • Location: Houston, TX
    • Craig's Neapolitan Garage
Re: FGM Raised Dome long awaited Modified Throat
« Reply #26 on: January 31, 2013, 07:26:38 PM »
3. Same as 1 (or 2 - does not matter much) - stuff the heck out of the oven with logs and keep stuffing.  This is the way I did the last two the same as each other.  It did heat up the fastest, but left the most coals.

I'm not surprised #3 left the most coals. You probably didn't have enough oxygen for that much wood.
"We make great pizza, with sourdough when we can, commercial yeast when we must, but always great pizza."
Craig's Neapolitan Garage

Offline mitchjg

  • Supporting Member
  • *
  • Posts: 2185
  • Location: Oakland, CA
Re: FGM Raised Dome long awaited Modified Throat
« Reply #27 on: January 31, 2013, 07:33:28 PM »
I'm not surprised #3 left the most coals. You probably didn't have enough oxygen for that much wood.
I was guessing that was the cause.  My thinking was to try 2 again but not be as aggressive in feeding it as before. - M
Mitch

Offline JD

  • Registered User
  • Posts: 1923
  • Location: Long Island, NY
Re: FGM Raised Dome long awaited Modified Throat
« Reply #28 on: January 31, 2013, 07:36:38 PM »
Jeff:

One concern Antoine has expressed is that my wood may not be fully seasoned and that almond may be a wood that produces an over abundance of coals rather than producing more flames.  I will not address that for a couple of months. 

Not sure where you are located but why not head to your local Lowes/HD/supermarket and buy a couple bags of seasoned firewood? Seems well worth the $10 to rule out under-seasoned wood.

Seasoned wood makes a tremendous difference in efficient firing as unseasoned wood wastes so much potential energy by changing water to steam.

My $0.02  :pizza:

Offline mitchjg

  • Supporting Member
  • *
  • Posts: 2185
  • Location: Oakland, CA
Re: FGM Raised Dome long awaited Modified Throat
« Reply #29 on: January 31, 2013, 07:40:56 PM »
Not sure where you are located but why not head to your local Lowes/HD/supermarket and buy a couple bags of seasoned firewood? Seems well worth the $10 to rule out under-seasoned wood.

Seasoned wood makes a tremendous difference in efficient firing as unseasoned wood wastes so much potential energy by changing water to steam.

My $0.02  :pizza:


I am in the SF Bay Area (Oakland).  I have no big allergy to trying that.  In theory, the place I purchased the wood is a reputable firewood dealer.  If I go to Lowes or someplace, I am not sure how I would know that their wood is seasoned any more or less?

Do I need to add some sort of moisture meter to my pizza oven arsenal?
Mitch

Offline mitchjg

  • Supporting Member
  • *
  • Posts: 2185
  • Location: Oakland, CA
Re: FGM Raised Dome long awaited Modified Throat
« Reply #30 on: January 31, 2013, 07:44:39 PM »
Mitch- Do you remember which way you fired in reply 12 here? I don't have near the experience as others in this dept but that looks like a lot of coals which would corroborate the poorly seasoned wood theory.

Again I have cooked in a WFO about a dozen times, but have had a wood fire place etc so I'm making a guess.

Sure do.  Both firings, with and without the insert, were number 3 - basically started with a pile as described in number 1 but followed up pretty shortly by stuffing the heck out of it and keeping it that way.

- Mitch
Mitch

Offline JD

  • Registered User
  • Posts: 1923
  • Location: Long Island, NY
Re: FGM Raised Dome long awaited Modified Throat
« Reply #31 on: January 31, 2013, 07:48:52 PM »
I am in the SF Bay Area (Oakland).  I have no big allergy to trying that.  In theory, the place I purchased the wood is a reputable firewood dealer.  If I go to Lowes or someplace, I am not sure how I would know that their wood is seasoned any more or less?

Do I need to add some sort of moisture meter to my pizza oven arsenal?

Last time I purchased a bag from Lowes it had right on it "Seasoned for a year" or something like that.... marketing or not, it was very dry and burned quickly.

My experience with burning wood is from using a wood-fired fireplace (stove), not really a WFO. The difference between firing seasoned wood and "nearly" seasoned wood is night and day.

Best part is if you find out your almond wood is a little wet, you know you'll have some great wood for next year. Absolutely nothing wasted.

I like to try simple solutions first... probably cause I'm cheap  ;D

Offline shuboyje

  • Registered User
  • Posts: 1242
  • Location: Detroit
Re: FGM Raised Dome long awaited Modified Throat
« Reply #32 on: January 31, 2013, 07:56:34 PM »
When I talk about it taking 10 hours to get mine ready, I'm starting with about 4 medium-small logs and then burning 1-2 medium-medium-large logs at a time for the balance of the 10 hours.

I need to try your way sometime and see how it goes.


In my second oven I found it did not scale well...I had to totally relearn how to fire it.  I think the ratio of door size to oven volume makes oxygen the limiting factor.  Small ovens have proportionally larger doors, and because of that can burn a proportionally larger quantity of wood.  I had to think a lot more to learn to fire my large oven, and I implement ideals I learned from reading about wood fired kilns.  I personally start a small fire in the middle with the sole goal of producing a pile of coals.  The coals then go to the back of the oven where I begin slowly adding wood.  As the coal pile at the back of the oven builds I start racking it forward until eventually the entire oven floor is covered by a thin layer of coals.  As the cool air comes in the oven it is at the bottom where it is preheated by the coals on it's way to the back.  By adding the wood at the back it tends to pyrolyse and produce a lot of volatile gases.  The volatile gases then combust with the preheated air and make for an intense fire as the heat moves back towards the front of the oven and eventually out the vent.    With this method I can get the oven to Neapolitan temps and fairly well saturated in about 3 hours.  I haven't done any big parties with the new oven so I'm not sure how well saturated it is, but I have cooked Coal oven style pizza in it without a live fire and actually get frustrated having to wait for the oven to cool.  
-Jeff

Offline mitchjg

  • Supporting Member
  • *
  • Posts: 2185
  • Location: Oakland, CA
Re: FGM Raised Dome long awaited Modified Throat
« Reply #33 on: January 31, 2013, 08:03:26 PM »
Last time I purchased a bag from Lowes it had right on it "Seasoned for a year" or something like that.... marketing or not, it was very dry and burned quickly.

My experience with burning wood is from using a wood-fired fireplace (stove), not really a WFO. The difference between firing seasoned wood and "nearly" seasoned wood is night and day.

Best part is if you find out your almond wood is a little wet, you know you'll have some great wood for next year. Absolutely nothing wasted.

I like to try simple solutions first... probably cause I'm cheap  ;D

That makes sense, I may call around.  We have a Home Depot and Ace Hardware close by.  The Lowes is more of a trek.  I do love your point about the wood not being a waste - just needs to be rescheduled.

Given, I stuffed the oven to the brim with almond when the oven was at about 200 C / 400 F , put the insulated door on it, and left the damper open - wouldn't you think that load of wood is now dried out?  It probably took a full 24 hours to get down to under 70 degrees.

- M
Mitch


Offline JD

  • Registered User
  • Posts: 1923
  • Location: Long Island, NY
Re: FGM Raised Dome long awaited Modified Throat
« Reply #34 on: January 31, 2013, 08:20:16 PM »
That makes sense, I may call around.  We have a Home Depot and Ace Hardware close by.  The Lowes is more of a trek.  I do love your point about the wood not being a waste - just needs to be rescheduled.

Given, I stuffed the oven to the brim with almond when the oven was at about 200 C / 400 F , put the insulated door on it, and left the damper open - wouldn't you think that load of wood is now dried out?  It probably took a full 24 hours to get down to under 70 degrees.

- M

I'm sure the surface of the wood is dried but I have no clue whether the core of the wood would be. Lots of factors involved and I'm certainly not an expert on kiln drying wood

If you find your almond wood is tough to get started, even with a lot of kindling, then I can almost guarantee its too wet. If it stays lit pretty easily then it's probably not the wood. The fact that you hear hissing is a huge red flag though.


Offline breadstoneovens

  • Vendor
  • *
  • Posts: 673
  • Location: Dallas, TX
    • Bread Stone Ovens
Re: FGM Raised Dome long awaited Modified Throat
« Reply #35 on: October 25, 2013, 09:30:59 PM »
After quite a few month of testing, and so on 3 different sizes ovens, we can safely say that the throat reducer doesn't improve the heat-up time.
Sorry Scott  :P

I guess we can say FGM knew what they were doing after all those years.

That said, with the help of some of my customers, we have developed a draft door.

The original idea was to create a spark arrestor door to help prevent any spark from jumping out of the oven. Pretty much just giving enough space to let the air in.
We noticed that this device served it purpose but also actually helped with eliminating the smoke when first firing the oven and improved the heat-up time.

I just got the first batch back from the welder today, let's paint them and  it is time to start a new thread.

Antoine



« Last Edit: October 25, 2013, 10:49:48 PM by breadstoneovens »
WFO cooking is about passion.

Offline mitchjg

  • Supporting Member
  • *
  • Posts: 2185
  • Location: Oakland, CA
Re: FGM Raised Dome long awaited Modified Throat
« Reply #36 on: October 25, 2013, 11:16:27 PM »
Sorry Scott, Antoine is right.  The throat reducer was very ineffective impacting heat up time.  I tried it several times.  It did have a small impact on more top heat, but not a lot.

On the new door, I will start a thread since I am one of the experimenters.

- Mitch
Mitch

Offline nickr

  • Registered User
  • Posts: 92
  • Location: United States
  • I Love Pizza!
Re: FGM Raised Dome long awaited Modified Throat
« Reply #37 on: October 31, 2013, 01:01:43 PM »
After quite a few month of testing, and so on 3 different sizes ovens, we can safely say that the throat reducer doesn't improve the heat-up time.
Sorry Scott  :P

I guess we can say FGM knew what they were doing after all those years.

That said, with the help of some of my customers, we have developed a draft door.

The original idea was to create a spark arrestor door to help prevent any spark from jumping out of the oven. Pretty much just giving enough space to let the air in.
We noticed that this device served it purpose but also actually helped with eliminating the smoke when first firing the oven and improved the heat-up time.

I just got the first batch back from the welder today, let's paint them and  it is time to start a new thread.

Antoine

Hello Everyone,

I've been following this thread closely as I have been looking at the 950BR but was concerned about the door to dome ratio and the possible inefficiencies there.

I am a bit surprised how quickly this device was deemed not to work. I only see one set of incomplete data. The fires were built for different reasons and it appears that a laser thermometer was not even used? There was also no mention of wood consumption (unless I missed it somewhere). Even in that test you can see a difference in temperature and it is stated that the smoke goes up the chimney.

I feel that if I bought this oven I would want the throat reducer. It's just a feeling but so much of it seems to make sense. Is there any actual full tests with data to support this as "not working".

Offline mitchjg

  • Supporting Member
  • *
  • Posts: 2185
  • Location: Oakland, CA
Re: FGM Raised Dome long awaited Modified Throat
« Reply #38 on: October 31, 2013, 10:07:16 PM »
Hello Everyone,

I've been following this thread closely as I have been looking at the 950BR but was concerned about the door to dome ratio and the possible inefficiencies there.

I am a bit surprised how quickly this device was deemed not to work. I only see one set of incomplete data. The fires were built for different reasons and it appears that a laser thermometer was not even used? There was also no mention of wood consumption (unless I missed it somewhere). Even in that test you can see a difference in temperature and it is stated that the smoke goes up the chimney.

I feel that if I bought this oven I would want the throat reducer. It's just a feeling but so much of it seems to make sense. Is there any actual full tests with data to support this as "not working".

Hi:

Antoine mentioned in his post that testing was done on 3 ovens.  One of them was mine.  I do not know who else was testing and on what ovens, so I cannot speak to that.  I can tell you that, although I only "published" data from one heat up, I have heated up several times with the door (perhaps a 1/2 dozen) and it did not make a meaningful difference.  I am pretty clear on how fast a heat up I will get under various conditions/approaches and I am confident that, for me and my oven, there was nothing about it that was particularly impactful.  No worthwhile difference in wood consumption nor in heat up time.  As I mentioned, I think I did get a little better top heat.  But, for me, it all seemed a bother.

Regarding the laser thermometer, I do not understand.  I have one and use it.  But, it is pretty useless while a fire is going.  With all the flames, the readings are off the scale.  And, for measuring heat up temperatures, I used the thermometer that is part of the oven - it measures the temperature in the core of the oven which is much more stable/objective than a surface reading.

Anyway, the whole matter was disappointing to me but I have moved on. I love trying new things like this and do not regret giving it a go.  But, no dice.

On the other hand, the use of the draft door has clearly made a difference to me.

You may want to ask Antoine about the other 2 folks if you think that will help you be convinced one way or the other.  In terms of the 950 BR, I have no experience or comment that would help you decide one way or the other.  There are many very knowledgeable experts on this forum and perhaps they can help guide or advise you.

best of luck,
Mitch

Mitch

scott123

  • Guest
Re: FGM Raised Dome long awaited Modified Throat
« Reply #39 on: November 01, 2013, 07:55:12 AM »
Sorry Scott  :P

Sorry Scott

If by saying 'sorry', you're congratulating me on being right, then thank you, it does feel pretty great finally having my ideas on this subject being fully vindicated  :P

Seriously, though, Antoine/Mitch, you do know that the indisputable success of the draft door thoroughly proves everything I've been saying, right? What is the draft door other than an extremely low throat?  My calculations were obviously a bit off in terms of the necessary height of the throat opening required to reveal a tangible difference, and, for that, I might need to nibble on a corner of my fedora ;) but my theory that a lower door shortens pre-heat times and saves  wood is, thanks to the draft door, no longer a theory, but proven fact.

It's quite simple, the opening in the throat prototype was too large to produce a discernible difference.  The draft door proves that it needs to be smaller.  Now, the total size of the opening in the draft door, when visualized as a single hole, isn't viable to work through as a throat, obviously, but you can certainly split the difference between the prototype and the draft and end up with time/energy savings and an opening that will allow the necessary access.

A prototype throat opening reduction of half the size should be perfect.  I don't think it's a coincidence that what I'm describing is pretty close to the opening size of a Stefano Ferrara.  I hate to sound like a broken record here, but the Italian oven builders have been doing this thing for quite some time and seem, for the most part, to know what they're doing.  I think it also reveals that door sizing, as Jeff (shuboyje) and Tom have pointed out on more than one occasion, is about more than just arbitrarily picking a height of 63% and expecting it to be perfect. A particular oven might perform better with a higher or (in this case) lower door, and you can't avoid taking the shape of the opening into account as well.

Rather than looking at doors just from a perspective of the ratio of their height to the height of the dome, I think it might be prudent to look at doors the same way we look at chimneys by calculating the total surface area of the opening. This would take shape into account a bit better and give us a much better idea of proper door sizing than the, imo, far oversimplified 63% figure.
« Last Edit: November 01, 2013, 08:23:38 AM by scott123 »

Offline shuboyje

  • Registered User
  • Posts: 1242
  • Location: Detroit
Re: FGM Raised Dome long awaited Modified Throat
« Reply #40 on: November 01, 2013, 09:40:30 AM »
The draft door  is in a different location then the ovens throat and functions in a different way.  Being outside the vent opening it does not function like a smaller opening.  In my opinion a draft door does two things.  It eliminates turbulence between the incoming air and the outgoing air, therefore increasing airflow, and it causes the oven to pressurize from natural draft also increasing airflow
-Jeff

scott123

  • Guest
Re: FGM Raised Dome long awaited Modified Throat
« Reply #41 on: November 01, 2013, 09:51:15 AM »
Crud. That's a good point, Jeff.  I guess I shouldn't be grabbing the champagne yet :)  Still, though, a throat reduction is basically two smaller doors- a smaller inside (pre-vent) door and a smaller outside door.  The success of the draft door proves the effectiveness of a smaller outside door. I still think the jury's still out on the effectiveness of a smaller inside door- I believe it's just a matter of going with a smaller opening than the prototype.


Offline mitchjg

  • Supporting Member
  • *
  • Posts: 2185
  • Location: Oakland, CA
Re: FGM Raised Dome long awaited Modified Throat
« Reply #42 on: November 01, 2013, 10:46:10 AM »
If I may, admittedly as one with little expertise in WFO design, this seems to be in a very theoretical space. 

Pragmatically, having experienced the throat reducer, there is a point where it is simply too much of a pain in the butt to use it if the door height is too low.

It seems to me that you can probably design a throat reducer that will also take on the effectiveness of a draft door.  But, it could be so low that I would give my oven away to a neighbor.  Maybe not, since I could use little skinny sticks of wood to get in the oven and move them around and since I try to keep the thickness factor low, so I guess it is still possible I could get a pie in and out of the oven.   8)
Mitch


 

pizzapan